Add snackbar

src/ui/SnackBar.cc

@@ -0,0 +1,143 @@
+#include <QDebug>
+#include <QPainter>
+
+#include "SnackBar.h"
+
+constexpr int STARTING_OFFSET = 1;
+
+SnackBar::SnackBar(QWidget *parent)
+  : OverlayWidget(parent)
+{
+        bgOpacity_  = 0.9;
+        duration_   = 6000;
+        boxWidth_   = 400;
+        boxHeight_  = 40;
+        boxPadding_ = 10;
+        textColor_  = QColor("white");
+        bgColor_    = QColor("#333");
+        offset_     = STARTING_OFFSET;
+        position_   = SnackBarPosition::Top;
+
+        QFont font("Open Sans", 14, QFont::Medium);
+        setFont(font);
+
+        showTimer_ = new QTimer();
+        hideTimer_ = new QTimer();
+        hideTimer_->setSingleShot(true);
+
+        connect(showTimer_, SIGNAL(timeout()), this, SLOT(onTimeout()));
+        connect(hideTimer_, SIGNAL(timeout()), this, SLOT(hideMessage()));
+}
+
+SnackBar::~SnackBar()
+{
+        stopTimers();
+
+        delete showTimer_;
+        delete hideTimer_;
+}
+
+void
+SnackBar::start()
+{
+        show();
+        raise();
+
+        showTimer_->start(10);
+}
+
+void
+SnackBar::hideMessage()
+{
+        stopTimers();
+        hide();
+
+        // Moving on to the next message.
+        messages_.removeFirst();
+
+        // Reseting the starting position of the widget.
+        offset_ = STARTING_OFFSET;
+
+        if (!messages_.isEmpty())
+                start();
+}
+
+void
+SnackBar::stopTimers()
+{
+        showTimer_->stop();
+        hideTimer_->stop();
+}
+
+void
+SnackBar::showMessage(const QString &msg)
+{
+        messages_.push_back(msg);
+
+        // There is already an active message.
+        if (isVisible())
+                return;
+
+        start();
+}
+
+void
+SnackBar::onTimeout()
+{
+        offset_ -= 0.5;
+
+        if (offset_ <= 0.0) {
+                showTimer_->stop();
+                hideTimer_->start(duration_);
+        }
+
+        update();
+}
+
+void
+SnackBar::mousePressEvent(QMouseEvent *)
+{
+        hideMessage();
+}
+
+void
+SnackBar::paintEvent(QPaintEvent *event)
+{
+        Q_UNUSED(event)
+
+        if (messages_.isEmpty())
+                return;
+
+        auto message_ = messages_.first();
+
+        QPainter p(this);
+        p.setRenderHint(QPainter::Antialiasing);
+
+        QBrush brush;
+        brush.setStyle(Qt::SolidPattern);
+        brush.setColor(bgColor_);
+        p.setBrush(brush);
+        p.setOpacity(bgOpacity_);
+
+        QRect r(0, 0, boxWidth_, boxHeight_);
+
+        p.setPen(Qt::white);
+        QRect br = p.boundingRect(r, Qt::AlignHCenter | Qt::AlignTop | Qt::TextWordWrap, message_);
+
+        p.setPen(Qt::NoPen);
+        r = br.united(r).adjusted(-boxPadding_, -boxPadding_, boxPadding_, boxPadding_);
+
+        const qreal s = 1 - offset_;
+
+        if (position_ == SnackBarPosition::Bottom)
+                p.translate((width() - (r.width() - 2 * boxPadding_)) / 2,
+                            height() - boxPadding_ - s * (r.height()));
+        else
+                p.translate((width() - (r.width() - 2 * boxPadding_)) / 2,
+                            s * (r.height()) - 2 * boxPadding_);
+
+        br.moveCenter(r.center());
+        p.drawRoundedRect(r.adjusted(0, 0, 0, 3), 3, 3);
+        p.setPen(textColor_);
+        p.drawText(br, Qt::AlignHCenter | Qt::AlignTop | Qt::TextWordWrap, message_);
+}